银杏垂乳个体发生及系统学意义  

Ontogenesis and Systematics Implications of Ginkgo biloba Chichi

作　　者：邢世岩[1] 张倩[1] 付兆军[1] 刘莉娟[1] 刘晓静[1] 辛红[1] 吴岐奎[1] 

机构地区：[1]山东农业大学林学院,泰安271018

出　　处：《林业科学》2013年第8期108-116,F0003,共10页Scientia Silvae Sinicae

基　　金：国家科技支撑计划课题(2012BAD21B04);山东省农业良种工程课题(201009);国家自然科学基金项目(31070589)

摘　　要：垂乳银杏是银杏家族中的一特异种质,银杏垂乳分根生、干生和枝生垂乳。中国现有垂乳银杏348株,分布在19个省(市),日本有43株。垂乳银杏与性别无关,但以300年以上古树居多。银杏垂乳呈圆锥状,外皮粗糙,并且垂直向下生长。这些垂乳生长到地面时可以产生根系和叶片。垂乳在树体上可以单一出现,也可以几个聚生。垂乳的顶部没有顶端分生组织,只出现形成层、次生木质部和韧皮部。从距垂乳顶端1cm处纵断面显示它的管胞具有许多取向,从距其顶端7cm处取的断面显示,管胞接近正常的形成层取向。银杏垂乳发生机制通常有生长素说、愈伤或不定芽说、环境诱变说、病变或衰老说、子叶芽说。银杏垂乳也许对该物种的生长、发育及营养繁殖、野生性及长寿命具有重要的生态学和系统学意义。Chichied ginkgo is a distinctive germplasm in ginkgo family.Ginkgo biloba chichi is divided into rooted chichi,stemmed chichi and branched chichi.There are 348 chichied ginkgo trees in China distributed in 19 provinces,and there are 43 plants in Japan.Chichied ginkgoes have no relations with gender but the most of chichied ginkgoes are older than 300 years.Chichi is coniform shaped with rough bark and grows vertically downward.These chichies can produce roots and leaves when they have grown down to the ground.Chichi on the tree can be a single appearance or a few aggregate.The tip of chichi has no apical meristem and only has cambium,secondary xylem and phloem.The median longitudinal sections exhibited various orientations of the tracheids at 1 cm from the tip of chichi.However,the sections revealed that tracheid orientation changed from being very variable in the centre to a more normal orientation as the cambium＇s at 7 cm from the tip.There are many theories on the chichi occurrence mechanisms,including Auxin theory,callus or adventitious bud theory,environmental mutagenesis theory,pathology or senility theory and cotyledon bud theory.Ginkgo biloba chichi probably has important ecology and systematics implications to the growth,development,vegetative propagation,wildness and long-lived of Ginkgo biloba.

关 键 词：银杏垂乳 解剖特征 个体发生 生长素 系统学 

分 类 号：S718.42[农业科学—林学]